Under rule changes announced Tuesday, which include a “modernized” inspection system, hog slaughter can be faster and maximum speeds have been removed. As a result, the USDA estimates average annual savings for large pork processing plants at $3.78 million as they increase production by 12.5%. However, opponents are worried it will affect food safety.

The changes come just as the world of pork is about to be turned on its head, with a deadly virus ravaging herds in China, the biggest producer and consumer. An unprecedented supply gap is expected to emerge as early as next year, and American hog producers are keen to fill the demand. There are already signs of pork shortages in China, with protein prices there hitting records.

Pork packers in the U.S. are already doing well as ample supplies keep down cash market prices for animals. According to HedgersEdge data, packers are making $40.30 a head, the highest this year.

The National Pork Producers Council and the North American Meat Institute praised the rule changes. Under the new inspection system, which is voluntary, government meat inspectors will have “more time to focus attention on verifying food safety and animal welfare requirements, and will stimulate food safety innovation,” the Meat Institute said in a statement.

But others raised concerns. More inspections will be done by the private companies themselves, rather than by government inspectors, said Patty Lovera, a program director for Food and Water Watch, an advocacy group in Washington D.C. That’s a flawed idea that could affect food safety, she said.

The United Food and Commercials Workers International Union has called increasing line speeds dangerous to workers in pork plants. Amanda Hitt, director of food integrity at the Government Accountability Project, said the new rules risk more repetitive motion injuries to line workers and rely too much on private employees who don’t have whistleblower protection to raise food safety issues.

“You’ve already got an industry that is notorious for injuries that has just been sped up,” Hitt said.

National Pork Producers Council President David Herring, a producer from Lillington, N.C., said the new rule “incentivizes investment in new technologies while ensuring a safe supply of wholesome American pork.”